Method for controlling shape, position and size of ultra-long common-bottom storage box in vertical assembling and welding mode

Abstract

The invention provides a method for controlling the shape, position and size of an ultra-long common-bottom storage box in a vertical assembling and welding mode. The method comprises a method for controlling the length between front and rear end frames of the storage box, a method for controlling the end face parallelism of the front and rear end frames of the storage box and a method for controlling the butt joint face coaxiality of the front and rear end frames of the storage box. The method for controlling the length between the front and rear end frames of the storage box is used for controlling the length between the front and rear end frames of the storage box to enable the length tolerance of the whole box to meet a preset tolerance range. The storage box front and rear end frame end face parallelism control method is used for regulating and controlling the parallelism of a box bottom supporting ring end frame connecting face and a lifting ring end frame connecting face, so that the storage box front and rear end frame end face parallelism meets a preset parallelism range. The storage box front and rear end frame butt joint surface coaxiality control method is used for regulating and controlling the coaxiality of a lifting ring end frame connecting surface and a box bottom supporting ring end frame connecting surface, so that the coaxiality of the storage box front and rear end frame butt joint surface meets a preset coaxiality range. By means of the method, high-quality and high-standard development and production of the ultra-long common-bottom storage box in the vertical assembling and welding mode are achieved.

Description

Technical Field

[0001] The present application belongs to the technical field of automated equipment for assembly and welding of large tanks of launch vehicles, and in particular to a method for controlling the shape, position and dimensions of an ultra-long common-bottom tank in a vertical assembly and welding mode. Background Art

[0002] At present, the maximum diameter of domestic launch vehicle fuel tanks is 5m and the length is 20m. The horizontal welding scheme is used for the welding production of the tank body. The length tolerance is required to be ≤10mm, the parallelism of the front and rear end frames is ≤4mm, and the coaxiality of the front and rear end frame joint surfaces of the tank body is ≤Φ10mm.

[0003] Comparison of the shape and size requirements of the new generation launch vehicle super-long common bottom tank and the current largest fuel tank Figure 2 As shown in the figure, through comparative analysis, the length tolerance control difficulty of the super-long common bottom tank of the new generation of launch vehicles is the same, and the requirements for the parallelism of the front and rear end frame end faces and the coaxiality of the front and rear end frame docking surfaces are doubled, which greatly increases the control difficulty.

[0004] The fuel tanks of my country's largest launch vehicles all adopt a horizontal welding mode and use tungsten inert gas welding technology. The box shape and size control technology and equipment can only meet the production requirements of tanks with a length of less than 20m between the front and rear end frames, and cannot meet the production requirements of 40m-class ultra-long common bottom tanks. Summary of the invention

[0005] In view of this, the present application aims to propose a method for controlling the shape and position dimensions of an ultra-long common-bottom tank in a vertical assembly and welding mode, so as to solve the problem that the shape and position dimension control technology for a 20m tank body cannot meet the production requirements of a 40m-class ultra-long common-bottom tank.

[0006] To achieve the above purpose, the technical solution of this application is implemented as follows:

[0007] The present application provides a method for controlling the shape and size of an ultra-long common-bottom tank in a vertical welding mode, including a method for controlling the length between the front and rear end frames of the tank, a method for controlling the parallelism of the end faces of the front and rear end frames of the tank, and a method for controlling the coaxiality of the butt joint surfaces of the front and rear end frames of the tank;

[0008] The method for controlling the length between the front and rear ends of the tank frame controls the length of the tank barrel section and measures and mills the length of the half tank before the tank is sealed and welded, so as to control the length between the front and rear ends of the tank frame, so that the length tolerance of the whole tank meets the predetermined tolerance range;

[0009] The method for controlling the parallelism of the end faces of the front and rear end frames of the tank calculates the parallelism by detecting the target point offset data through a laser measurement array, and adjusts the parallelism of the connection surface of the end frame of the bottom support ring and the connection surface of the end frame of the lifting ring by correcting the mechanical coordinates of the lifting mechanism, so that the parallelism of the end faces of the front and rear end frames of the tank meets the predetermined parallelism range;

[0010] The method for controlling the coaxiality of the butt joint surfaces of the front and rear end frames of the tank calculates the coaxiality by detecting the target point offset data through a laser measurement array, and adjusts the coaxiality of the end frame connection surface of the lifting ring and the end frame connection surface of the bottom support ring by correcting the center coordinates of the lifting ring, so that the coaxiality of the butt joint surfaces of the front and rear end frames of the tank meets the predetermined coaxiality range.

[0011] Furthermore, the method for controlling the length between the front and rear end frames of the tank includes:

[0012] The actual length of the barrel section is controlled by the standard barrel section control method: the theoretical length of the barrel section + 4.5mm, the tolerance is ±1mm, so that the length tolerance of the whole box is controlled within 15mm;

[0013] A plurality of laser targets are set at the end face of the end frame on one side of the tank where welding has been completed. A laser rangefinder is used to measure the lengths of a plurality of target points on the end face of the half-tank sealing ring seam to be welded. The average length of the half-tank is obtained based on the lengths of the plurality of target points. The milling amount of the edge to be welded of the half-tank sealing welding is calculated by the average length of the half-tank, the theoretical length between the front and rear end frames of the tank and the height of the front bottom assembly measured before the front bottom assembly is put on the shelf for sealing welding. After the milling is completed, the sealing welding is carried out.

[0014] Furthermore, the calculation formula for the milling amount of the half-box to be welded edge of the box sealing welding is:

[0015] δ=La+Lb-L0-2;

[0016] Where La represents the height of the front bottom assembly, Lb represents the average length of half a tank, and L0 represents the theoretical length between the front and rear end frames of the tank.

[0017] Furthermore, the method for controlling the parallelism of the end faces of the front and rear end frames of the tank includes a method for measuring the parallelism of the end faces of the front and rear end frames, including:

[0018] Arrange the laser measurement array circumferentially on the connection surface of the bottom frame of the lifting ring box, and arrange the laser target array circumferentially on the support ring at the bottom of the box, corresponding to the axis of the laser measurement array;

[0019] Before the storage container is put on the shelf, the laser target position is measured by the target, and the parallelism of the connection surface of the box bottom support ring end frame and the connection surface of the lifting ring end frame is calculated according to the target offset of multiple target positions.

[0020] Furthermore, the method for controlling the parallelism of the end faces of the front and rear end frames of the tank also includes a method for correcting the parallelism of the end faces of the front and rear end frames, including:

[0021] Fix the bottom support ring, correct the coordinates of the lifting mechanism connected to the lifting ring according to the calculated parallelism of the bottom support ring end frame connection surface and the lifting ring end frame connection surface, update the corrected coordinate value to a new parallelism reference coordinate, adjust the position of the lifting ring end frame connection surface based on the new parallelism reference coordinate to regulate the parallelism of the bottom support ring end frame connection surface and the lifting ring end frame connection surface, and control the parallelism of the front and rear end frame end surfaces of the storage tank within a predetermined parallelism range.

[0022] Furthermore, the method for controlling the coaxiality of the butt joint surfaces of the front and rear end frames of the tank includes a method for measuring the coaxiality of the butt joint surfaces of the front and rear end frames, including:

[0023] A laser measuring instrument is set at the center point of the lifting ring, and a laser target is set at the center point of the bottom support ring. Before the storage container product is put on the shelf, the laser target point position is measured by the target, and the coaxiality of the bottom support ring end frame connection surface and the lifting ring end frame connection surface is calculated according to the target offset of multiple target points.

[0024] Furthermore, the method for controlling the coaxiality of the butt joint surfaces of the front and rear end frames of the tank further comprises:

[0025] Fix the bottom support ring, correct the lifting ring according to the calculated coaxiality of the bottom support ring end frame connection surface and the lifting ring end frame connection surface, and update the corrected coordinate value to a new coaxiality reference coordinate, and adjust the center point position of the lifting ring based on the new coaxiality reference coordinate to regulate the coaxiality of the lifting ring end frame connection surface and the bottom support ring end frame connection surface, so as to control the coaxiality of the docking surface of the front and rear end frames of the storage tank within a predetermined coaxiality range.

[0026] Furthermore, the theoretical center points of the box bottom support ring end frame connection surface and the lifting ring end frame connection surface are determined and marked when the end face positioning pin holes and connection holes are processed by numerical control.

[0027] Compared with the prior art, the method for controlling the shape, position and size of an ultra-long common-bottom tank in a vertical welding mode described in this application has the following beneficial effects:

[0028] The method for controlling the shape and position dimensions of an extra-long common bottom tank in a vertical assembly and welding mode described in the present application can control the length between the front and rear end frames of the extra-long common bottom tank, the parallelism of the end faces of the front and rear end frames, and the coaxiality of the front and rear end frame butt surfaces within the tolerance range required by the design, thereby achieving high-quality and high-standard research and production of products. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0030] Figure 1A schematic diagram of the tank structure and main shape, position and dimensions described in an embodiment of the present application;

[0031] Figure 2 A comparison diagram of the shape and size requirements of the super-long tank described in the embodiment of the present application and the existing maximum tank;

[0032] Figure 3 This is a schematic diagram of the device layout of the method for precise measurement and milling of a box before sealing according to an embodiment of the present application;

[0033] Figure 4 This is a schematic diagram of the vertical welding state of the super-long common bottom storage tank described in the embodiment of the present application;

[0034] Figure 5 This is a schematic diagram of measuring the parallelism of the front and rear end frame connection surfaces according to an embodiment of the present application;

[0035] Figure 6 This is a schematic diagram of laser target offset measurement according to an embodiment of the present application;

[0036] Figure 7 This is a schematic diagram of the parallelism adjustment of the lifting ring according to the embodiment of the present application;

[0037] Figure 8 This is a schematic diagram of the positioning of the center point of the connection surface between the box bottom support ring and the lifting ring end frame described in the embodiment of the present application;

[0038] Fig. 9 This is a schematic diagram of measuring the coaxiality of the butt joint surfaces of the front and rear end frames of the tank according to the embodiment of the present application;

[0039] Fig.10 This is a schematic diagram of the coaxiality adjustment of the lifting ring described in an embodiment of the present application. DETAILED DESCRIPTION

[0040] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0041] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be the usual meanings understood by people with ordinary skills in the field to which the present application belongs. The "first", "second" and similar words used in the embodiments of the present application do not represent any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing in front of the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0042] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0043] Explanation of professional terms:

[0044] Common bottom tank: The fuel tank and the oxidant tank are combined into one tank, and the fuel and oxidant are separated by the common bottom inside the tank.

[0045] Tank bottom assembly: includes the front bottom assembly and the rear bottom assembly, which are welded together by the tank bottom and the short shell, and participate in the welding of the tank as an integral component.

[0046] End frame: includes the front end frame and the rear end frame, which are located on the short shells of the front bottom assembly and the rear bottom assembly respectively. It is an important connecting surface between the tank and other rocket body structures.

[0047] my country's new generation of carrier rocket fuel tanks are characterized by super-long, new structure and high requirements. The tank diameter is 5m, the length is 40m, and the bottom tank structure is common (the tank structure and main shape and position dimensions are shown in the figure). Figure 1 As shown in the figure, the box body is welded and produced by vertical welding scheme. The box body has high manufacturing standards and strict shape and size requirements. Within the scale range of 40m, the length tolerance between the front and rear end frames of the box body is required to be ≤20mm, the parallelism of the end faces of the front and rear end frames is ≤4mm, and the coaxiality of the joint surfaces of the front and rear end frames of the box body is ≤Φ10mm.

[0048] Since the fuel tank of my country's largest carrier rocket currently adopts a horizontal welding mode and uses tungsten inert gas welding technology, the tank shape and size control technology and equipment can only meet the production requirements of tanks with a length of less than 20m between the front and rear end frames. Currently, there is no shape and size control technology for ultra-long common bottom tanks with a length of 40m.

[0049] Based on the above content, this application develops a technology for controlling the shape and position dimensions of an extra-long common bottom tank under the vertical assembly and welding mode, and controls the length between the front and rear end frames of the extra-long common bottom tank, the parallelism of the end faces of the front and rear end frames, and the coaxiality of the front and rear end frame docking surfaces within the design tolerance range, thereby achieving high-quality and high-standard development and production of products.

[0050] The method for controlling the shape and size of an extra-long common-bottom tank in a vertical welding mode described in this embodiment mainly includes a method for controlling the length between the front and rear end frames of the tank, a method for controlling the parallelism of the end faces of the front and rear end frames of the tank, and a method for controlling the coaxiality of the butt surfaces of the front and rear end frames of the tank. This embodiment describes the above control methods in detail one by one.

[0051] 1. Method for controlling the length between the front and rear frames of the tank

[0052] The method for controlling the length between the front and rear end frames of the super-long common bottom tank in the present application adopts the method of precise measurement and matching milling before the standard barrel section and the tank body are sealed, so that the length tolerance of the whole box is controlled within the range of 5mm.

[0053] (1) Standard barrel section control method:

[0054] The super-long tank is mainly composed of front and rear short shells, front and rear tank bottoms, common bottoms and several barrel sections. The main factor affecting the tank length is the barrel section length. By controlling the barrel section length within a relatively precise range, the tank body length can be effectively controlled. After analysis and verification, the actual barrel section length is controlled within: the theoretical length of the barrel section + 4.5mm, with a tolerance of ±1mm, and the tolerance of the entire tank length can be controlled within 15mm;

[0055] (2) Method for precise measurement and milling of the tank body before sealing:

[0056] By measuring and milling the half-box length before the tank is sealed and welded, the length between the front and rear end frames of the tank can be further accurately controlled. The theoretical length between the front and rear end frames of the tank is L0. Before the front bottom assembly is put on the shelf for sealing and welding, the height La of the front bottom assembly is measured on the measuring platform.

[0057] like Figure 3 and Figure 4 As shown in the figure, a laser target is set at the end face of the end frame of one side of the tank where welding has been completed, and the target is evenly set at 4 locations around the tank. The laser rangefinder is used to measure the lengths of the four target points on the end face of the half-tank sealing circumferential seam to be welded, and the average length of the half-tank is obtained by Lb = (L1 + L2 + L3 + L4) / 4, and the matching milling amount of the half-tank to be welded edge of the sealing welding is δ = La + Lb-L0-2 (the fixed value 2 here is a standard value set according to work experience). After the matching milling is completed, the sealing welding is carried out. The precision measurement and matching milling method before the box is sealed can further control the length tolerance of the whole box within 5mm.

[0058] 2. Method for controlling the parallelism of the front and rear end frames of the tank

[0059] The method for controlling the parallelism of the front and rear end frames of the tank in the present application includes a method for measuring the parallelism of the front and rear end frames and a method for correcting the parallelism of the front and rear end frames, and controls the parallelism of the front and rear end frames of the tank within a range of 4 mm.

[0060] In this embodiment, the parallelism of the front and rear end frames of the tank product is controlled by controlling the parallelism of the equipment tooling connection surface connecting the front and rear end frames of the super-long tank. The butt joint surfaces connected to the front and rear end frames of the super-long tank are the tank bottom support ring end frame connection surface and the lifting ring end frame connection surface. Measurement and adjustment are performed before the tank is put on the shelf for production. During the measurement and adjustment, the distance between the tank bottom support ring end frame connection surface and the lifting ring end frame connection surface is adjusted to the theoretical length position of the tank. The vertical assembly welding state of the super-long common bottom tank is shown in the figure below. Figure 4 shown.

[0061] like Figure 5 As shown, in order to achieve the parallelism measurement and precise control of the connection surface of the bottom support ring end frame and the connection surface of the lifting ring end frame in the vertical mode within a spacing scale of more than 35m, this application uses a laser measurement array to detect the target offset data to calculate the parallelism, and corrects the mechanical coordinates of the lifting mechanism to achieve precise measurement and adjustment control of the parallelism of the connection surface of the bottom support ring end frame and the connection surface of the lifting ring end frame. The specific explanation is as follows:

[0062] (1) Method for measuring the parallelism of the front and rear end frames:

[0063] The laser measurement array is arranged on the connection surface of the bottom frame of the lifting ring box, evenly distributed in 4 places in the circumferential direction, and the laser target array is arranged on the bottom support ring of the box, evenly distributed in 4 places in the circumferential direction, corresponding to the axis of the laser measurement array. It should be noted that when the parallelism is 0, the lasers of the 4 laser measurement arrays hit the center position of their corresponding targets.

[0064] Before the container products are put on the shelves, start the parallelism laser measurement program and measure the laser target point position through the target, such as Figures 6 to 8 As shown in the figure, if the laser target position is offset, the target will transmit the measured target offset X and target offset Y to the system computer. The system computer calculates the parallelism of the box bottom support ring end frame connection surface and the lifting ring end frame connection surface through the target offsets at the four positions, and displays the parallelism on the operation interface.

[0065] (2) Method for correcting the parallelism of the front and rear end frames:

[0066] In order to achieve precise adjustment of parallelism, the bottom support ring of the box is fixed, and the axial position of the lifting ring is adjusted to adapt to the parallelism of the bottom support ring of the box. The lifting ring and the vertical frame are supported at 4 places, and each support is equipped with an independent servo lifting mechanism to achieve stable lifting movement and parallelism adjustment.

[0067] If the detected parallelism exceeds the process requirement, the system computer will adjust the coordinate values ​​of the four lifting mechanisms connected to the lifting ring and update the corrected coordinate values ​​to new parallelism reference coordinates, and adjust the position of the lifting ring end frame connection surface based on the new parallelism reference coordinates, thereby realizing the regulation of the parallelism of the lifting ring end frame connection surface and the box bottom support ring end frame connection surface, and then realizing the control of the parallelism of the front and rear end frame docking surfaces of the extra-long common bottom tank.

[0068] The method for calculating parallelism is as follows: This embodiment is explained by taking four sets of rangefinders as an example, and the measurement heights of the four sets of rangefinders are L1, L2, L3, and L4 respectively;

[0069] Parallelism N = max(L1..L4)-min(L1..L4);

[0070] The correction method is as follows:

[0071] 1) Taking L1 as the reference, the other three servo lifting mechanisms are adjusted according to the difference between their height measurement values ​​and L1. The adjustment amounts are ΔL2 = L1-L2; ΔL3 = L1-L3; ΔL4 = L1-L4.

[0072] 2) After adjustment, the rangefinder measures the adjusted height.

[0073] 3) Calculate the parallelism; if the parallelism index is not met, repeat step 1); if it is met, the adjustment is completed.

[0074] 3. Method for controlling the coaxiality of the butt joint surfaces of the front and rear end frames of the tank:

[0075] The method for controlling the coaxiality of the butt joint surfaces of the front and rear end frames of the tank in the present application includes a method for measuring the coaxiality of the butt joint surfaces of the front and rear end frames and a method for correcting the coaxiality of the butt joint surfaces of the front and rear end frames, and controls the coaxiality of the butt joint surfaces of the front and rear end frames of the tank within the range of Φ10mm.

[0076] This embodiment controls the coaxiality of the butt joint surfaces of the front and rear end frames of the storage tank product by controlling the coaxiality of the central axis of the lifting ring end frame connection surface and the central axis of the box bottom support ring end frame connection surface. Measurement and adjustment are performed before the storage tank product is put on the shelf for production. During the measurement and adjustment, the distance between the box bottom support ring end frame connection surface and the lifting ring end frame connection surface is adjusted to the theoretical length position of the storage tank.

[0077] In order to achieve accurate assembly welding and control product quality, when the tank products are assembled on the shelf, the bottom assembly end frame is connected and fixed with the equipment bottom support ring end frame connection surface and the lifting ring end frame connection surface by pin positioning + connecting bolt fixing method. The theoretical axis of the tank bottom assembly end frame is the same as the theoretical axis of the bottom support ring end frame connection surface and the lifting ring end frame connection surface. Fig. 9As shown, the theoretical center points of the connection surfaces of the box bottom support ring end frame and the lifting ring end frame are determined and marked by CNC machining the end face positioning pin holes and connection holes. The specific explanation is as follows:

[0078] (1) Method for measuring the coaxiality of the front and rear end frame butt surfaces:

[0079] like Fig. 9 As shown, in this embodiment, a laser measuring instrument is set at the center point of the lifting ring, and a laser target is set at the center point of the box bottom support ring. It should be noted that when the coaxiality is 0, the laser target point of the laser measuring instrument at the center of the lifting ring should be directly opposite to the center position of the target of the box bottom support ring.

[0080] Before the storage tank products are put on the shelves, the coaxiality laser measurement program is started, and the target measures the laser target point position. If the laser target point position is offset, the target will transmit the measured target point offset X and target point offset Y to the system computer. The system computer calculates the coaxiality of the connection surface of the bottom support ring end frame and the connection surface of the lifting ring end frame through the target point offsets of the four positions, and displays the coaxiality on the operation interface.

[0081] (2) Method for correcting the coaxiality of the front and rear end frame butt joints:

[0082] In order to achieve precise adjustment of coaxiality, the bottom support ring is fixed, and the lifting ring is adjusted in the horizontal plane to align with the axis of the bottom support ring. The position adjustment of the lifting ring in the horizontal plane adopts a multi-point sliding method, such as Fig.10 As shown in the figure, a sliding platform is set at the position where the lifting ring is connected to each lifting mechanism. Each sliding platform can move and link independently in the X and Y directions, so that the center point of the lifting ring can be positioned and fixed at any point within the circular range of a radius of 50mm. If the detected coaxiality exceeds the process requirement, the system computer adjusts the sliding platform, trims the coordinate value of the center of the lifting ring, and updates the corrected coordinate value to the new coaxiality reference coordinate, thereby realizing the regulation of the coaxiality of the lifting ring end frame connection surface and the box bottom support ring end frame connection surface, and then realizing the control of the coaxiality of the front and rear end frame docking surface of the super-long common bottom tank.

[0083] It should be noted that the coaxiality measurement algorithm used in this embodiment is based on the prior art. The coaxiality correction is based on the feedback values ​​X', Y' of the sensor.

[0084] Algorithm principle: The deviation values ​​ΔX=X0-X', ΔY=Y0-Y' between the reference position X0, Y0 and the measured position X', Y' are taken as the errors of the X and Y servo motors of the centering mechanism. The displacements of the X and Y servo motors of the centering mechanism are adjusted through PID control to eliminate the errors, so that the measured position and the reference position coincide with each other and the coaxiality of the product is realized.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

[0086] The embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the scope of protection of the present application.

Claims

1. A method for controlling the shape, position and size of an ultra-long common-bottom storage tank in a vertical welding mode, characterized in that: It includes a method for controlling the length between the front and rear end frames of a tank, a method for controlling the parallelism of the end faces of the front and rear end frames of a tank, and a method for controlling the coaxiality of the butt joint faces of the front and rear end frames of a tank; The method for controlling the length between the front and rear ends of the tank frame controls the length of the tank barrel section and measures and mills the length of the half tank before the tank is sealed and welded, so as to control the length between the front and rear ends of the tank frame, so that the length tolerance of the whole tank meets the predetermined tolerance range; The method for controlling the parallelism of the end faces of the front and rear end frames of the tank calculates the parallelism by detecting the target point offset data through a laser measurement array, and adjusts the parallelism of the connection surface of the end frame of the bottom support ring and the connection surface of the end frame of the lifting ring by correcting the mechanical coordinates of the lifting mechanism, so that the parallelism of the end faces of the front and rear end frames of the tank meets the predetermined parallelism range; The method for controlling the coaxiality of the butt joint surfaces of the front and rear end frames of the tank calculates the coaxiality by detecting the target point offset data through a laser measurement array, and adjusts the coaxiality of the end frame connection surface of the lifting ring and the end frame connection surface of the bottom support ring by correcting the center coordinates of the lifting ring, so that the coaxiality of the butt joint surfaces of the front and rear end frames of the tank meets the predetermined coaxiality range.

2. The method according to claim 1, characterized in that The method for controlling the length between the front and rear end frames of the storage tank comprises: The actual length of the barrel section is controlled by the standard barrel section control method: the theoretical length of the barrel section + 4.5mm, with a tolerance of ±1mm, so that the length tolerance of the entire box is controlled within 15mm; A plurality of laser targets are set at the end face of the end frame on one side of the tank where welding has been completed. A laser rangefinder is used to measure the lengths of a plurality of target points on the end face of the half-tank sealing ring seam to be welded. The average length of the half-tank is obtained based on the lengths of the plurality of target points. The milling amount of the edge to be welded of the half-tank sealing welding is calculated by the average length of the half-tank, the theoretical length between the front and rear end frames of the tank and the height of the front bottom assembly measured before the front bottom assembly is put on the shelf for sealing welding. After the milling is completed, the sealing welding is carried out.

3. The method according to claim 2, characterized in that The calculation formula for the milling amount of the half-box to be welded edge for box sealing welding is: δ=La+Lb-L0-2; Where La represents the height of the front bottom assembly, Lb represents the average length of half a tank, and L0 represents the theoretical length between the front and rear end frames of the tank.

4. The method according to claim 1, characterized in that: The method for controlling the parallelism of the end faces of the front and rear end frames of the storage tank includes a method for measuring the parallelism of the end faces of the front and rear end frames, including: Arrange the laser measurement array circumferentially on the connection surface of the bottom frame of the lifting ring box, and arrange the laser target array circumferentially on the support ring at the bottom of the box, corresponding to the axis of the laser measurement array; Before the storage container is put on the shelf, the laser target position is measured by the target, and the parallelism of the connection surface of the box bottom support ring end frame and the connection surface of the lifting ring end frame is calculated according to the target offset of multiple target positions.

5. The method according to claim 4, characterized in that The method for controlling the parallelism of the end faces of the front and rear end frames of the storage tank also includes a method for correcting the parallelism of the end faces of the front and rear end frames, including: Fix the bottom support ring, correct the coordinates of the lifting mechanism connected to the lifting ring according to the calculated parallelism of the bottom support ring end frame connection surface and the lifting ring end frame connection surface, update the corrected coordinate value to a new parallelism reference coordinate, adjust the position of the lifting ring end frame connection surface based on the new parallelism reference coordinate to regulate the parallelism of the bottom support ring end frame connection surface and the lifting ring end frame connection surface, and control the parallelism of the front and rear end frame end surfaces of the storage tank within a predetermined parallelism range.

6. The method according to claim 1, characterized in that The method for controlling the coaxiality of the butt joint surfaces of the front and rear end frames of the tank includes a method for measuring the coaxiality of the butt joint surfaces of the front and rear end frames, including: A laser measuring instrument is set at the center point of the lifting ring, and a laser target is set at the center point of the bottom support ring. Before the storage container product is put on the shelf, the laser target point position is measured by the target, and the coaxiality of the bottom support ring end frame connection surface and the lifting ring end frame connection surface is calculated according to the target offset of multiple target points.

7. The method according to claim 6, characterized in that The method for controlling the coaxiality of the butt joint surfaces of the front and rear end frames of the storage tank further comprises: Fix the bottom support ring, correct the lifting ring according to the calculated coaxiality of the bottom support ring end frame connection surface and the lifting ring end frame connection surface, and update the corrected coordinate value to a new coaxiality reference coordinate, and adjust the center point position of the lifting ring based on the new coaxiality reference coordinate to regulate the coaxiality of the lifting ring end frame connection surface and the bottom support ring end frame connection surface, so as to control the coaxiality of the docking surface of the front and rear end frames of the storage tank within a predetermined coaxiality range.

8. The method according to claim 6, characterized in that: The theoretical center points of the box bottom support ring end frame connection surface and the lifting ring end frame connection surface are determined and marked by CNC machining the end face locating pin holes and connection holes.

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